About: http://webisa.webdatacommons.org/403974115

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Is it a local minimum? (You are aiming for a contradiction, because you are assuming that there is a point where $f(y)\gt f(x_0)$, and you are trying to show there is no such point).
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com